This invention relates to a carton and a blank for making the carton, and more specifically to a self closing carton of triangular cross sectional configuration.
Numerous types of cartons or containers of all sizes, shapes and configurations are readily available. However, as the configuration of the carton changes from a common rectangular box-like configuration, the blank becomes of more complex construction and requires more costly and time consuming manufacture, as well as presenting more difficulty in folding the blank to form the completed carton.
A further problem with many existing cartons, is that while they may be formed of a single blank, after folded into a completed shape, the carton must be sealed by means of various adhesives. The adhesives may be printed as part of the carton whereby portions of the carton must be heat sealed. In other situations, adhesives are added after the carton has been completed. Additionally, tapes may be needed to close off portions of the carton in order to seal it.
For elongated types of material, such as documents, manuscripts, rolls of postage stamps, etc., it has been found that the most convenient type of carton for transporting and shipping such documents is a tubular or cylindrical carton. The document can then be rolled and placed in the carton. The ends of the carton can typically be sealed off with plugs or other end closure device. Additionally, tapes can be pasted at the ends of the carton and the tapes folded inside the tubular cartons in order to seal off the ends. Such cartons are frequently used for mailing, and are frequently referred to as mailing tubes.
While such cylindrical or tubular cartons or containers are very useful for various types of documents and other material which cannot be folded, the cylindrical containers themselves are extremely awkward to use, store and ship. Although they provide good protection for their contents by avoiding the necessity of folding, the storage and transport of the containers themselves present a problem. Tubular or cylindrical containers must be shipped in their final condition. Thus, a manufacturer of the tubular containers must actually ship them as tubes. This takes up a considerable amount of shipping space. Also, the user must store the containers in its tubular shape, whereby an excessive amount of storage space is also required. An additional problem concerns the closure of the tubular containers. Generally the tubular containers are not self closing and require the addition of closure material. Such closure material must be pasted on at the time of manufacture or must be provided separately as insertable plugs or covers. Accordingly, an excessive amount of time and expense is required for storing, shipping and utilizing of such tubular containers.